Refractory castable for low nickel matte chute and preparation method thereof

Abstract

The present invention provides a refractory castable for low-matte nickel chute and a preparation method thereof. The raw materials for preparing the castable include the following components in parts by mass: 6 to 15 parts of alumina particles or their recycled granular materials, 25 to 40 parts of corundum particles or their recycled granular materials, 20 to 30 parts of silicon carbide particles or their recycled granular materials, 1 to 10 parts of corundum fine powder, 5 to 15 parts of silicon carbide fine powder, 4 to 10 parts of alumina micropowder, 3.4 to 10 parts of binder, 3 to 10 parts of antioxidant, and 2 to 4 parts of carbon material; wherein the antioxidant is a combination of metallic silicon powder, silicon carbide micropowder and Si-N-O micropowder. In the castable, metallic silicon powder, silicon carbide micropowder and Si-N-O micropowder can form columnar mullite and O'-sialon phase in the matrix, which has a significant toughening effect; a higher proportion of silicon carbide is added, and the multi-grade particle size of particles, fine powder and micropowder is matched to better play the performance characteristics of silicon carbide non-wetting, anti-oxidation and high hardness and wear resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of refractory materials, and in particular relates to a refractory castable for a low-matte nickel chute and a preparation method thereof. Background Art

[0002] The nickel smelting process from nickel sulfide ores (such as pentlandite) produces an intermediate product, nickel matte, containing approximately 20%-40% nickel, along with impurities such as copper, iron, and sulfur. Nickel sulfide ore is smelted at high temperatures (1200°C-1400°C) to produce nickel matte (Ni+Cu content approximately 20%-40%) and slag (primarily FeSiO₃). The viscosity of molten nickel matte is typically 0.01-0.1 Pa·s, similar to that of liquid iron and much lower than that of slag, resulting in a highly fluid melt. Its viscosity decreases significantly with increasing temperature. Nickel matte chutes are trough-shaped equipment used to transport and transfer nickel matte. These chutes are typically constructed of refractory materials. Nickel matte melts corrode refractory containers primarily through a combination of chemical penetration, oxidation-reduction reactions, and thermomechanical erosion.

[0003] Compared with blast furnace ironmaking, low-grade nickel matte has stronger chemical corrosion, penetration, and oxidation effects on refractory materials. This is because, first of all, the Ni and Cu metal phases in low-grade nickel matte easily penetrate the pores of refractory materials and further react with SiC in Al2O3-SiC refractory materials. Ni+SiC→Ni-Si alloy+C, thereby destroying the SiC reinforcement phase of the refractory material, causing the material structure to be destroyed and damaged rapidly. Secondly, due to the high content of FeS and Cu2S in low-grade nickel matte slag, the permeability to refractory materials is enhanced, and the high SiO2 / Al2O3 ratio accelerates the slag reaction. Therefore, the large amount of slag and high impurity content are the main causes of refractory damage. Oxygen-enriched slag-making process is also used in the low-grade nickel matte smelting process to slag and remove impurities, but the oxides in the slag can cause oxidation of the matrix in the refractory material, making the structure loose, reducing strength, and exacerbating erosion damage.

[0004] The Chinese patent document with publication number CN202411385599 discloses an Al2O3-SiC-C refractory castable product and its preparation method. Its ingredients mainly include corundum particles, silicon carbide particles, corundum fine powder, silicon carbide fine powder, activated alumina powder, binder, antioxidant, additives, etc. The binder is light-burned magnesium oxide powder, and the antioxidant is passivated metal aluminum powder. This castable product has high strength when used in iron ditch for ironmaking, and has good resistance to slag corrosion and permeability. However, when used in low-matte nickel chute, its antioxidant performance, corrosion resistance, permeability resistance, and high-temperature strength performance are insufficient, and its binder will cause the volume of the castable to change, resulting in increased porosity and decreased strength. Summary of the Invention

[0005] The technical problem solved by the present invention is to provide a refractory castable for low nickel matte chute and a preparation method thereof. The addition of an antioxidant composed of metallic silicon powder, silicon carbide micropowder and Si-NO micropowder can form columnar mullite and solid solution O'-sialon phase in the matrix, which has a significant reinforcing and toughening effect; a higher proportion of silicon carbide is added, and a multi-level particle size combination of particles, fine powder and micropowder is adopted to better play the non-wetting, anti-oxidation and high hardness and wear-resistant performance characteristics of silicon carbide, and significantly improve the high temperature strength, thermal shock stability, corrosion resistance and anti-penetration performance of the castable.

[0006] In order to solve the above problems, one aspect of the present invention provides a refractory castable for a low-matte nickel chute, the raw materials for preparing the refractory castable include the following components in parts by mass:

[0007] 6-15 parts of alumina particles or recycled particles thereof, 25-40 parts of corundum particles or recycled particles thereof, 20-30 parts of silicon carbide particles or recycled particles thereof, 1-10 parts of corundum fine powder, 5-15 parts of silicon carbide fine powder, 4-10 parts of alumina micropowder, 3.4-10 parts of binder, 3-10 parts of antioxidant, and 2-4 parts of carbon material; wherein the antioxidant is a combination of metallic silicon powder, silicon carbide micropowder and Si-NO micropowder.

[0008] Preferably, the raw materials for its preparation include the following components in parts by mass:

[0009] 6-10 parts of alumina particles or their recycled particles, 28-35 parts of corundum particles or their recycled particles, 25-30 parts of silicon carbide particles or their recycled particles, 1-5 parts of corundum fine powder, 6-10 parts of silicon carbide fine powder, 6-10 parts of alumina micropowder, 3.4-7 parts of binder, 5-9 parts of antioxidant, and 2-3 parts of carbon material.

[0010] Preferably, the mass ratio of alumina powder to antioxidant is 1:0.625~1.25.

[0011] Preferably, the antioxidant is a combination of metallic silicon powder, silicon carbide powder and Si-NO powder in a mass ratio of 2:2-4:2-4.

[0012] Preferably, the binder is a mixture of silica powder and aluminate cement in a mass ratio of 1:0.5~1.5, or the binder is a mixture of silica powder, Cyc-Z, and aluminate cement in a mass ratio of 0.7:2~3:0.5~1.5, or the binder is a mixture of silica powder, silica sol, and aluminate cement in a mass ratio of 1.5:4~6:0.6~0.8.

[0013] Preferably, the following components are also included in percentage by mass:

[0014] Water reducing agent 0.1%~0.3%, boron carbide 0.2%~0.8%, explosion-proof agent 0.07%~0.25%.

[0015] Preferably, the silicon carbide particles or recycled particles thereof are composed of silicon carbide particles or recycled particles thereof with a particle size of 1 to 3 mm and silicon carbide particles or recycled particles thereof with a particle size of 0.1 to 1 mm, mixed in a mass ratio of 10 to 13:14 to 17;

[0016] The silicon carbide fine powder is composed of 200-mesh silicon carbide fine powder and 325-mesh silicon carbide fine powder mixed in a mass ratio of 5-10:1-4;

[0017] The particle size of silicon carbide powder is 1~5μm;

[0018] The corundum particles or the recovered particles thereof include brown corundum particles or the recovered particles thereof with a particle size of 5-8 mm, brown corundum particles or the recovered particles thereof with a particle size of 3-5 mm, and dense corundum particles or the recovered particles thereof with a particle size of 1-3 mm; the mass ratio of alumina particles or the recovered particles thereof with a particle size of 8-15 mm, brown corundum particles or the recovered particles thereof with a particle size of 5-8 mm, brown corundum particles or the recovered particles thereof with a particle size of 3-5 mm, and dense corundum particles or the recovered particles thereof with a particle size of 1-3 mm is 6-10:12-17:14-17:2-5;

[0019] The particle size of the corundum fine powder is 200 mesh;

[0020] The particle size of the alumina particles or the recovered particles is 8 to 15 mm;

[0021] The particle size of metallic silicon powder is 3~40μm;

[0022] The particle size of Si-NO powder is 0.5~20μm;

[0023] The particle size of alumina powder is 2~5μm;

[0024] The particle size of carbon material is 0.001~2mm;

[0025] The particle size of boron carbide is 325 mesh.

[0026] Preferably, the content of Al2O3 in the alumina particles is not less than 87wt%, the content of Fe2O3 is not higher than 1.55%, the porosity is less than 5.5%, and the bulk density is greater than 3.3g / cm 3 ;

[0027] The Al2O3 content in the recovered alumina pellets and corundum pellets is not less than 90wt%, and the bulk density is ≥3.7g / cm 3 ;

[0028] The SiC content in the silicon carbide particles is not less than 92wt%;

[0029] The SiC content in the silicon carbide fine powder is not less than 97wt%;

[0030] The SiO2 content in the silica powder is not less than 92wt%;

[0031] The SiO2 content in the silica sol is 39wt%~41wt%, the pH is 9~10.5 at 25℃, and the viscosity is 10~20mPa·s;

[0032] The Al2O3 content in aluminate cement is not less than 70wt%.

[0033] Preferably, the carbon material is one or a combination of spherical pitch, graphite, and carbon black;

[0034] The water reducer is one or a combination of SP610, FS20, FDN, DF401, PC8159, and BC-2;

[0035] The explosion-proof agent is one or a combination of metal aluminum powder and explosion-proof fiber.

[0036] Another aspect of the present invention provides a method for preparing the above-mentioned refractory castable for low-matte nickel chute, comprising the following steps:

[0037] S1. The raw materials of the antioxidant are mixed to obtain an antioxidant mixture;

[0038] S2. The antioxidant mixture and the binder are mixed to obtain a premix;

[0039] S3. Mix alumina particles or their recycled particles, corundum particles or their recycled particles, silicon carbide particles or their recycled particles, corundum fine powder, silicon carbide fine powder, alumina micropowder, carbon material, and premix to obtain the refractory castable for the low nickel matte chute, wherein silica sol is added to the binder when in use.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] The refractory castable for low nickel matte chute of the present invention is added with an antioxidant composed of metallic silicon powder, silicon carbide micropowder and Si-NO micropowder. First, metallic silicon powder, silicon carbide micropowder and Si-NO micropowder can form a continuous glaze layer on the surface of the castable to block the pores under high temperature, and coat the refractory material to prevent the refractory material from being further oxidized; secondly, each component in the antioxidant is ultrafine powder, and the filling effect of the micropowder on the micropores in the castable matrix is ​​utilized to improve the density of the castable, reduce the oxidation of the castable by oxygen or oxygen-rich substances, improve the density of the matrix, and can improve the solid-phase sintering strength of the castable earlier and faster, so that the refractory castable for low nickel matte melt chute has lower porosity, stronger antioxidant and slag erosion resistance. More importantly, and also the key innovation of the present invention, is that the SiO2 generated by oxidation of the metallic silicon powder and Si-NO powder in the antioxidant, and the silica powder in the binder react with the alumina powder in the matrix to form columnar mullite; at high temperatures, the SiO gas phase and SiNO formed by oxidation of the metallic silicon powder and Si-NO powder react with the alumina powder in the matrix to form a substitutional solid solution O'-sialon phase; the metallic silicon powder reacts with the carbon source in the matrix to form SiC whiskers. The whiskers, columnar crystals, and O'-sialon phase formed by the above reactions have significant reinforcing and toughening effects, which can significantly improve the high-temperature strength, thermal shock stability, corrosion resistance, and anti-permeation properties of the castable. In addition, the above-mentioned powders have high activity and react with the alumina powder in the matrix to form a mullite phase. The slight volume expansion further fills the pores generated in the castable, improving the castable's antioxidant properties and strength.

[0042] The refractory castable for the low nickel matte chute of the present invention uses a higher proportion of silicon carbide compared to the existing iron trough castable, and the silicon carbide adopts a multi-level particle size combination of granules, fine powder and micropowder, which can improve the uniformity of silicon carbide distribution, and better play the performance characteristics of silicon carbide such as non-wetting, anti-oxidation (an oxide film is formed on the surface to slow down continuous oxidation) and high hardness and wear resistance. It can effectively cope with the high permeability, oxidation and scouring effect of low nickel matte melt, thereby improving its service life.

[0043] The castable of the present invention is applied to low nickel matte chutes, has strong applicability, is easy to construct, can be used to make various special-shaped prefabricated parts or for local hot repair and maintenance, and has significant advantages in saving resources, reducing costs, improving construction efficiency, and increasing service life. DETAILED DESCRIPTION

[0044] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0045] The chute used for low-grade nickel matte smelting is limited by the site. Both the prefabricated parts and the castable construction have a thin working layer thickness. The low-grade nickel matte melt has low viscosity, strong penetration, and a large amount of slag, which causes severe chemical corrosion to the refractory materials. The melt flow has a high scouring strength on the refractory materials. The commonly used iron trough castables cannot meet the slag resistance and thermal shock stability requirements during high-temperature service on the low-grade nickel matte chute, resulting in abnormal erosion and peeling of the refractory materials, affecting normal use.

[0046] One aspect of an embodiment of the present invention provides a refractory castable for a low-matte nickel chute, wherein the raw materials for preparing the refractory castable include the following components in parts by mass:

[0047] 6-15 parts of alumina particles or recycled particles thereof, 25-40 parts of corundum particles or recycled particles thereof, 20-30 parts of silicon carbide particles or recycled particles thereof, 1-10 parts of corundum fine powder, 5-15 parts of silicon carbide fine powder, 4-10 parts of alumina micropowder, 3.4-10 parts of binder, 3-10 parts of antioxidant, and 2-4 parts of carbon material; wherein the antioxidant is a combination of metallic silicon powder, silicon carbide micropowder and Si-NO micropowder.

[0048] The refractory castable for low nickel matte chute in the embodiment of the present invention is added with an antioxidant composed of metallic silicon powder, silicon carbide micropowder and Si-NO micropowder. First, metallic silicon powder, silicon carbide micropowder and Si-NO micropowder can form a continuous glaze layer on the surface of the castable to block the pores under high temperature, and coat the refractory material to prevent the refractory material from being further oxidized; secondly, each component in the antioxidant is ultrafine powder, and the filling effect of the micropowder on the micropores in the castable matrix is ​​utilized to improve the density of the castable, reduce the oxidation of the castable by oxygen or oxygen-rich substances, improve the density of the matrix, and can improve the solid-phase sintering strength of the castable earlier and faster, so that the refractory castable for low nickel matte melt chute has lower porosity, stronger antioxidant and slag erosion resistance. More importantly, and also the key innovation of the present invention, is that the SiO2 generated by oxidation of the metallic silicon powder and Si-NO powder in the antioxidant, and the silica powder in the binder react with the alumina powder in the matrix to form columnar mullite; at high temperatures, the SiO gas phase and SiNO formed by oxidation of the metallic silicon powder and Si-NO powder react with the alumina powder in the matrix to form a substitutional solid solution O'-sialon phase; the metallic silicon powder reacts with the carbon source in the matrix to form SiC whiskers. The whiskers, columnar crystals, and O'-sialon phase formed by the above reactions have significant reinforcing and toughening effects, which can significantly improve the high-temperature strength, thermal shock stability, corrosion resistance, and anti-permeation properties of the castable. In addition, the above-mentioned powders have high activity and react with the alumina powder in the matrix to form a mullite phase. The slight volume expansion further fills the pores generated in the castable, improving the castable's antioxidant properties and strength.

[0049] The refractory castable for the low nickel matte chute in the embodiment of the present invention uses a higher proportion of silicon carbide compared to the existing iron trough castable, and the silicon carbide adopts a multi-grade particle size combination of granules, fine powder and micropowder, which can improve the uniformity of silicon carbide distribution, better exert the non-wetting, anti-oxidation (an oxide film is formed on the surface to slow down continuous oxidation) and high hardness and wear resistance performance characteristics of silicon carbide, and can effectively cope with the high permeability, oxidation and scouring effects of low nickel matte melt, thereby improving service life.

[0050] The castable of the present invention is applied to low nickel matte chutes, has strong applicability, is easy to construct, can be used to make various special-shaped prefabricated parts or for local hot repair and maintenance, and has significant advantages in saving resources, reducing costs, improving construction efficiency, and increasing service life.

[0051] Preferably, the raw materials for its preparation include the following components in parts by mass:

[0052] 6-10 parts of alumina particles or their recycled particles, 28-35 parts of corundum particles or their recycled particles, 25-30 parts of silicon carbide particles or their recycled particles, 1-5 parts of corundum fine powder, 6-10 parts of silicon carbide fine powder, 6-10 parts of alumina micropowder, 3.4-7 parts of binder, 5-9 parts of antioxidant, and 2-3 parts of carbon material.

[0053] Moreover, if too much binder is added, more high-temperature liquid phase will be introduced, which will reduce the high-temperature strength. If too little binder is added, the curing strength of the castable will be low, which is not conducive to demoulding and baking. If too much antioxidant is added, the viscosity of the castable will increase and the construction performance will be significantly reduced. If too little is added, the oxide film cannot be continuously formed, which will reduce the antioxidant performance of the castable. Only when the amount of binder and antioxidant added is moderate can the castable be guaranteed to have good construction performance and performance. The refractory castable for low nickel matte chute of the present invention, when adopting the above-mentioned preferred mass fraction, has a low water addition amount and good fluidity, which is more conducive to the construction of the castable, promotes the densification and improves the strength of the castable, and the castable has better high-temperature strength, thermal shock stability, corrosion resistance and penetration resistance.

[0054] Preferably, the mass ratio of alumina powder to antioxidant is 1:0.625-1.25. Alumina powder can react with SiO2 generated after oxidation of the antioxidant to form columnar mullite. It can also react with the unoxidized metallic silicon powder and Si-NO powder in the antioxidant to form SiO gas and SiNO at high temperatures to form a substitutional solid solution O'-sialon phase, thereby achieving a toughening effect. It can also react with the antioxidant to form a mullite phase, resulting in a certain volume expansion, filling pores, and improving castable performance. Therefore, the alumina powder and antioxidant need to have an appropriate mass ratio to produce an appropriate amount of columnar mullite and O'-sialon phase, and to produce an appropriate volume expansion, thereby improving the castable's high-temperature strength, thermal shock stability, corrosion resistance, and anti-penetration properties.

[0055] Preferably, the antioxidant is a combination of metallic silicon powder, silicon carbide powder, and Si-NO powder in a mass ratio of 2:2-4:2-4. An appropriate mass ratio of metallic silicon powder, silicon carbide powder, and Si-NO powder in the antioxidant can produce an appropriate amount of columnar mullite and O'-sialon phase, and produce appropriate volume expansion, thereby improving the castable's high-temperature strength, thermal shock stability, corrosion resistance, and permeation resistance. Further preferably, the antioxidant is a combination of metallic silicon powder, silicon carbide powder, and Si-NO powder in a mass ratio of 2:3:3.

[0056] Preferably, the binder is a mixture of silica powder and aluminate cement in a mass ratio of 1:0.5-1.5, or a mixture of silica powder, Cyc-Z, and aluminate cement in a mass ratio of 0.7:2-3:0.5-1.5, or a mixture of silica powder, silica sol, and aluminate cement in a mass ratio of 1.5:4-6:0.6-0.8. Further preferably, the binder is a mixture of silica powder and aluminate cement in a mass ratio of 1:1, or a mixture of silica powder, Cyc-Z, and aluminate cement in a mass ratio of 0.7:2.5:1, or a mixture of silica powder, silica sol, and aluminate cement in a mass ratio of 1.5:5:0.7.

[0057] The refractory castable for the low-matte nickel chute of the embodiment of the present invention has three binders to choose from, which can be applied to different construction environments and exert more excellent performance. The first is a composite binder of silica micropowder and aluminate cement; the second is a composite binder of silica micropowder, CYC-Z, and aluminate cement; and the third is a composite binder of silica micropowder, silica sol, and aluminate cement. These three forms of binders have the following beneficial effects on the castable: First, the different binders are used in combination to reduce the amount of aluminate cement added to the castable, reduce the CaO content, reduce the content of low-melting phase generated at high temperature, have better high-temperature strength, and improve anti-scouring performance; secondly, the castables of the first and second binders are directly added with water during construction, and can be applied to cold and hot construction. Among them, the castable with the first binder can produce higher strength through natural curing in a cold environment, but it requires a certain curing time. The castable with the second binder quickly produces strength in a hot environment, shortening the curing time. During the construction of the castable with the third binder, silica sol solution is added. No free water is added to the castable, which is conducive to rapid baking and is especially suitable for pouring and ramming construction under hot conditions.

[0058] Preferably, the following components are also included in percentage by mass:

[0059] Water reducing agent 0.1%~0.3%, boron carbide 0.2%~0.8%, explosion-proof agent 0.07%~0.25%.

[0060] Among them, boron carbide has certain antioxidant properties.

[0061] Preferably, the silicon carbide particles or recycled particles thereof are composed of silicon carbide or recycled particles with a particle size of 1-3 mm and silicon carbide or recycled particles with a particle size of 0.1-1 mm, respectively, mixed in a mass ratio of 10-13:14-17; the silicon carbide fine powder is composed of 200-mesh silicon carbide fine powder and 325-mesh silicon carbide fine powder mixed in a mass ratio of 5-10:1-4; the particle size of the silicon carbide powder is 1-5 μm.

[0062] The refractory castable for the low nickel matte chute in the embodiment of the present invention adopts a multi-level particle size combination of silicon carbide, including granules, fine powder and micro powder, to improve the uniformity of silicon carbide distribution, better exert the non-wetting, anti-oxidation and high hardness and wear-resistant performance characteristics of silicon carbide, and can effectively cope with the high permeability, oxidation and scouring effects of low nickel matte melt, thereby improving service life.

[0063] Preferably, the particle size of the alumina particles or the recovered particles thereof is 8 to 15 mm.

[0064] Preferably, the corundum particles or their recycled particles include brown corundum particles or their recycled particles with a particle size of 5-8 mm, brown corundum particles or their recycled particles with a particle size of 3-5 mm, and dense corundum particles or their recycled particles with a particle size of 1-3 mm; the mass ratio of alumina particles or their recycled particles with a particle size of 8-15 mm, brown corundum particles or their recycled particles with a particle size of 5-8 mm, brown corundum particles or their recycled particles with a particle size of 3-5 mm, and dense corundum particles or their recycled particles with a particle size of 1-3 mm is 6-10:12-17:14-17:2-5.

[0065] Preferably, the particle size of the corundum fine powder is 200 mesh.

[0066] Preferably, the particle size of metallic silicon powder is 3-40 μm; the particle size of Si-NO powder is 0.5-20 μm; and the particle size of alumina powder is 2-5 μm. Using ultrafine powders of these particle sizes for each component of the antioxidant can better fill the micropores in the castable matrix, increase the density of the castable, and reduce oxidation of the castable by oxygen or oxygen-rich substances.

[0067] Preferably, the particle size of the carbon material is 0.001-2 mm.

[0068] Preferably, the particle size of the boron carbide is 325 mesh.

[0069] Preferably, the content of Al2O3 in the alumina particles is not less than 87wt%, the content of Fe2O3 is not higher than 1.55%, the porosity is less than 5.5%, and the bulk density is greater than 3.3g / cm 3 .

[0070] Preferably, the content of Al2O3 in the recovered alumina particles and the recovered corundum particles is not less than 90wt%, and the bulk density is ≥3.7g / cm 3 .

[0071] Preferably, the SiC content in the silicon carbide particles is not less than 92 wt %; more preferably, the SiC content is ≥ 97 wt %.

[0072] Preferably, the SiC content in the silicon carbide fine powder is not less than 97 wt %.

[0073] Preferably, the SiO2 content in the silica powder is not less than 92wt%; more preferably, the SiO2 content is ≥95%.

[0074] Preferably, the SiO2 content in the silica sol is 39 wt% to 41 wt%, the pH is 9 to 10.5 at 25°C, and the viscosity is 10 to 20 mPa·s.

[0075] Preferably, the Al2O3 content in aluminate cement is not less than 70wt%.

[0076] Preferably, the carbon material is one or a combination of spherical pitch, graphite, and carbon black. Further preferably, the carbon material is spherical pitch and carbon black. The spherical pitch has a particle size of 0.2-1 mm and a melting point of 160°C. The carbon black can be various currently available grades, such as N220, N330, N550, N660, and N990. Preferably, N990 is used.

[0077] Preferably, the water reducer is one or a combination of SP610, FS20, FDN, DF401, PC8159, and BC-2. Preferably, the water reducer is PC8159.

[0078] Preferably, the boron carbide has a particle size of 325 mesh and a total boron content of ≥96%.

[0079] The explosion-proof agent is one or a combination of aluminum powder and explosion-proof fiber. Preferably, the explosion-proof agent comprises 0.05-0.15 parts aluminum powder and 0.02-0.1 parts explosion-proof fiber. The aluminum powder has a particle size of no greater than 100 mesh, and the explosion-proof fiber has a melting point of less than 160°C.

[0080] Another aspect of the present invention provides a method for preparing the above-mentioned refractory castable for low-matte nickel chute, comprising the following steps:

[0081] S1. The raw materials of the antioxidant are mixed to obtain an antioxidant mixture;

[0082] S2. The antioxidant mixture and the binder are mixed to obtain a premix;

[0083] S3. Mix alumina particles or their recycled particles, corundum particles or their recycled particles, silicon carbide particles or their recycled particles, corundum fine powder, silicon carbide fine powder, alumina micropowder, carbon material, and premix to obtain the refractory castable for the low nickel matte chute, wherein silica sol is added to the binder when in use.

[0084] In the following embodiments, the content of Al2O3 in the alumina particles is not less than 87wt%, the content of Fe2O3 is not higher than 1.55%, the porosity is less than 5.5%, and the bulk density is greater than 3.3g / cm 3 The Al2O3 content in the recovered alumina pellets and corundum pellets is not less than 90wt%, and the bulk density is ≥3.7g / cm 3The SiC content in silicon carbide particles is not less than 92wt%; the SiC content in silicon carbide fine powder is not less than 97wt%; the SiO2 content in silicon dioxide micropowder is not less than 92wt%; the SiO2 content in silica sol is 39wt%~41wt%, the pH is 9~10.5 at 25℃, and the viscosity is 10~20mPa·s; the Al2O3 content in aluminate cement is not less than 70wt%; the total boron in boron carbide is ≥96%.

[0085] Example 1

[0086] The low-matte nickel chute refractory castable of this embodiment is prepared from raw materials including the following components in parts by mass:

[0087] 6 parts of 88 homogenized alumina particles with a particle size of 8-15mm, 14 parts of brown corundum particles with a particle size of 5-8mm, 15 parts of brown corundum particles with a particle size of 3-5mm, 3 parts of dense corundum particles with a particle size of 1-3mm, 2 parts of dense corundum fine powder with a particle size of 200 mesh, 12 parts of 97 silicon carbide particles with a particle size of 1-3mm, 17 parts of silicon carbide particles with a particle size of 0.1-1mm, 7 parts of silicon carbide fine powder with a particle size of 200 mesh, 2 parts of silicon carbide fine powder with a particle size of 325 mesh, 8 parts of activated alumina fine powder with a particle size of 2-5μm, 2 parts of silica fine powder, 2 parts of aluminate cement, 2 parts of metallic silicon powder with a particle size of 3-40μm, 3 parts of 97 silicon carbide fine powder with a particle size of 3μm, 3 parts of Si-NO fine powder with a particle size of 0.5-20μm, carbon black N990 0.5 parts, 2 parts of spherical asphalt with a particle size of 0.2-1mm, 0.1 parts of metal aluminum powder with a particle size of 200 mesh, 0.05 parts of explosion-proof fiber, 0.2 parts of water reducer PC8159, and 0.8 parts of boron carbide with a particle size of 325 mesh.

[0088] The method for preparing the refractory castable for the low nickel matte chute of this embodiment comprises the following steps:

[0089] (1) Prepare the components of the antioxidant according to the required proportions and mix them evenly using a high-speed planetary mixer to obtain an antioxidant mixture;

[0090] (2) The antioxidant mixture, binder, metal aluminum powder, explosion-proof fiber, water reducer and boron carbide are mixed evenly to obtain a premixed material;

[0091] (3) Put the granular material, fine powder and premixed small materials in the raw materials into the planetary mixer and mix them evenly to obtain the finished castable material;

[0092] (4) When the finished castable is used, add 4.5% water and stir thoroughly to obtain a wet mix. Pour the wet mix into a mold or construction surface and it can be put into use after curing and baking.

[0093] Example 2

[0094] The refractory castable for the low nickel matte chute of this embodiment is prepared by using the same raw materials as in Example 1 in terms of other components and mass fractions, with the difference being that the binder is 2 parts of CYCLE-Z, 0.7 parts of silica powder, and 0.75 parts of aluminate cement.

[0095] The preparation method of the refractory castable for the low nickel matte chute in this embodiment is the same as that in Example 1.

[0096] Example 3

[0097] The refractory castable for the low nickel matte chute of this embodiment is prepared by using the same raw materials as in Example 1 in terms of other components and mass fractions, with the difference being that the binder is 1.5 parts of silica powder, 5 parts of silica sol, and 0.7 parts of aluminate cement.

[0098] The method for preparing the refractory castable for the low nickel matte chute of this embodiment comprises the following steps:

[0099] (1) The components of the antioxidant are prepared in the required proportions and mixed evenly using a high-speed planetary mixer to obtain an antioxidant mixture;

[0100] (2) The antioxidant mixture, binder (except silica sol), metal aluminum powder, explosion-proof fiber, water reducer and boron carbide are mixed evenly to obtain a premixed small material;

[0101] (3) Put the granular material, fine powder and premixed small materials in the raw materials into the planetary mixer and mix them evenly to obtain the finished castable material;

[0102] (4) When the finished castable is used, add silica sol solution (concentration of 5%) and stir thoroughly to obtain a wet mix. Pour the wet mix into a mold or construction surface and put it into use after curing and baking.

[0103] Example 4

[0104] The refractory castable for the low-matte nickel chute of this embodiment is prepared by using the same raw materials and the same mass fractions as those in Example 2, except that the alumina particles with a particle size of 8-15 mm, brown corundum particles, brown corundum particles with a particle size of 5-8 mm, and brown corundum particles with a particle size of 3-5 mm are replaced by alumina and brown corundum iron ditch recycled materials of the same particle size and mass fraction, and the Al2O3 in the recycled materials is ≥90wt% and the bulk density is ≥3.7g / cm 3 .

[0105] The preparation method of the refractory castable for the low nickel matte chute in this embodiment is the same as that in Example 2.

[0106] Example 5

[0107] The refractory castable for the low nickel matte chute of this embodiment is prepared by using the same raw materials as in Example 2 in terms of other components and mass fractions, with the difference being that 200-mesh dense corundum is replaced by 5 parts and silicon carbide micropowder is replaced by 0 parts.

[0108] The preparation method of the refractory castable for the low nickel matte chute in this embodiment is the same as that in Example 2.

[0109] Example 6

[0110] The refractory castable for the low nickel matte chute of this embodiment is prepared by using the same raw materials as in Example 2 in terms of other components and mass fractions, with the difference being that 200-mesh dense corundum is replaced by 3 parts and silicon carbide micropowder is replaced by 2 parts.

[0111] The preparation method of the refractory castable for the low nickel matte chute in this embodiment is the same as that in Example 2.

[0112] Example 7

[0113] The refractory castable for the low nickel matte chute of this embodiment is prepared by using the same raw materials as in Example 2 in terms of other components and mass fractions, with the difference being that 200-mesh dense corundum is replaced by 1 part and silicon carbide micropowder is replaced by 4 parts.

[0114] The preparation method of the refractory castable for the low nickel matte chute in this embodiment is the same as that in Example 2.

[0115] Example 8

[0116] The refractory castable for the low nickel matte chute of this embodiment is prepared by using the same raw materials as in Example 2 in terms of other components and mass fractions, with the difference being that 200-mesh dense corundum is replaced by 4 parts and Si-NO micropowder is replaced by 0 parts.

[0117] The preparation method of the refractory castable for the low nickel matte chute in this embodiment is the same as that in Example 2.

[0118] Example 9

[0119] The refractory castable for the low nickel matte chute of this embodiment is prepared by using the same raw materials as in Example 2 in terms of other components and mass fractions, with the difference being that 200-mesh dense corundum is replaced by 2 parts and Si-NO powder is replaced by 2 parts.

[0120] The preparation method of the refractory castable for the low nickel matte chute in this embodiment is the same as that in Example 2.

[0121] Example 10

[0122] The refractory castable for the low-matte nickel chute of this embodiment is prepared by using the same raw materials as in Example 2 in terms of other components and mass fractions, with the difference being that 200-mesh dense corundum is replaced by 0 parts and Si-NO powder is replaced by 4 parts.

[0123] The preparation method of the refractory castable for the low nickel matte chute in this embodiment is the same as that in Example 2.

[0124] Example 11

[0125] The refractory castable for the low-matte nickel chute of this embodiment is prepared from raw materials including the following components in parts by mass:

[0126] 10 parts of 88 homogenized alumina particles with a particle size of 8-15mm, 12 parts of brown corundum particles with a particle size of 5-8mm, 14 parts of brown corundum particles with a particle size of 3-5mm, 2 parts of dense corundum particles with a particle size of 1-3mm, 5 parts of dense corundum fine powder with a particle size of 200 mesh, 11 parts of 97 silicon carbide particles with a particle size of 1-3mm, 14 parts of silicon carbide particles with a particle size of 0.1-1mm, 7 parts of silicon carbide fine powder with a particle size of 200 mesh, 3 parts of silicon carbide fine powder with a particle size of 325 mesh, 6 parts of activated alumina fine powder with a particle size of 2-5μm, and Sai Ke-Z 2 parts, 0.7 parts of silica powder, 0.7 parts of aluminate cement, 2 parts of metallic silicon powder with a particle size of 3~40μm, 3 parts of 97 silicon carbide powder with a particle size of 3μm, 3 parts of Si-NO powder with a particle size of 0.5~20μm, 1 part of carbon black N990, 1 part of spherical asphalt with a particle size of 0.2-1mm, 0.05 parts of metallic aluminum powder with a particle size of 200 mesh, 0.02 parts of explosion-proof fiber, 0.3 parts of water reducer PC8159, and 0.2 parts of boron carbide with a particle size of 325 mesh.

[0127] The preparation method of the refractory castable for the low nickel matte chute described in this embodiment is the same as that in Example 2.

[0128] Example 12

[0129] The refractory castable for the low-matte nickel chute of this embodiment is prepared from raw materials including the following components in parts by mass:

[0130] 6 parts of 88 homogenized alumina particles with a particle size of 8-15mm, 15 parts of brown corundum particles with a particle size of 5-8mm, 15 parts of brown corundum particles with a particle size of 3-5mm, 5 parts of dense corundum particles with a particle size of 1-3mm, 1 part of dense corundum fine powder with a particle size of 200 mesh, 13 parts of 97 silicon carbide particles with a particle size of 1-3mm, 17 parts of silicon carbide particles with a particle size of 0.1-1mm, 5 parts of silicon carbide fine powder with a particle size of 200 mesh, 1 part of silicon carbide fine powder with a particle size of 325 mesh, 8 parts of activated alumina fine powder with a particle size of 2-5μm, and Sai Ke-Z 3 parts, silica powder 2 parts, aluminate cement 2 parts, metallic silicon powder with a particle size of 3~40μm 2 parts, 97 silicon carbide powder with a particle size of 3μm 3 parts, Si-NO powder with a particle size of 0.5~20μm 3 parts, carbon black N990 1 part, spherical asphalt with a particle size of 0.2-1mm 2 parts, metallic aluminum powder with a particle size of 200 mesh 0.15 parts, explosion-proof fiber 0.1 part, water reducer PC8159 0.1 part, boron carbide with a particle size of 325 mesh 0.8 parts.

[0131] The preparation method of the refractory castable for the low nickel matte chute described in this embodiment is the same as that in Example 2.

[0132] Example 13

[0133] The refractory castable for the low-matte nickel chute of this embodiment is prepared from raw materials including the following components in parts by mass:

[0134] 15 parts of 88 homogenized alumina particles with a particle size of 8-15mm, 10 parts of brown corundum particles with a particle size of 5-8mm, 13 parts of brown corundum particles with a particle size of 3-5mm, 2 parts of dense corundum particles with a particle size of 1-3mm, 10 parts of dense corundum fine powder with a particle size of 200 mesh, 8 parts of 97 silicon carbide particles with a particle size of 1-3mm, 12 parts of silicon carbide particles with a particle size of 0.1-1mm, and 200 mesh carbide particles. 10 parts of silicon fine powder, 5 parts of silicon carbide fine powder with a particle size of 325 mesh, 4 parts of activated alumina fine powder with a particle size of 2~5μm, 2 parts of Cyclic-Z, 0.7 parts of silicon dioxide fine powder, 0.7 parts of aluminate cement, 0.75 parts of metallic silicon powder with a particle size of 3~40μm, 1.125 parts of 97 silicon carbide fine powder with a particle size of 3μm, 1.125 parts of Si-NO fine powder with a particle size of 0.5~20μm, 1 part of carbon black N990, 1 part of spherical asphalt with a particle size of 0.2-1mm, 0.1 part of metallic aluminum powder with a particle size of 200 mesh, 0.05 parts of explosion-proof fiber, 0.2 parts of water reducer PC8159, and 0.8 parts of boron carbide with a particle size of 325 mesh.

[0135] The preparation method of the refractory castable for the low nickel matte chute described in this embodiment is the same as that in Example 2.

[0136] Example 14

[0137] The low-matte nickel chute refractory castable of this embodiment is prepared from raw materials including the following components in parts by mass:

[0138] 6 parts of 88 homogenized alumina particles with a particle size of 8-15mm, 16 parts of brown corundum particles with a particle size of 5-8mm, 17 parts of brown corundum particles with a particle size of 3-5mm, 7 parts of dense corundum particles with a particle size of 1-3mm, 1 part of dense corundum fine powder with a particle size of 200 mesh, 13 parts of 97 silicon carbide particles with a particle size of 1-3mm, 17 parts of silicon carbide particles with a particle size of 0.1-1mm, 4 parts of silicon carbide fine powder with a particle size of 200 mesh, 1 part of silicon carbide fine powder with a particle size of 325 mesh, 8 parts of activated alumina fine powder with a particle size of 2-5μm, and Sai Ke-Z 4 parts, 3 parts of silica powder, 3 parts of aluminate cement, 2.5 parts of metallic silicon powder with a particle size of 3~40μm, 3.75 parts of 97 silicon carbide powder with a particle size of 3μm, 3.75 parts of Si-NO powder with a particle size of 0.5~20μm, 2 parts of carbon black N990, 2 parts of spherical asphalt with a particle size of 0.2-1mm, 0.1 part of metallic aluminum powder with a particle size of 200 mesh, 0.05 part of explosion-proof fiber, 0.2 part of water reducer PC8159, and 0.8 part of boron carbide with a particle size of 325 mesh.

[0139] The preparation method of the refractory castable for the low nickel matte chute described in this embodiment is the same as that in Example 2.

[0140] Example 15

[0141] The remaining components and proportions of the raw materials used in the preparation of the low-grade nickel matte chute of this embodiment are the same as those of Example 2, with the following differences: the antioxidant contains 2.67 parts of metallic silicon powder, 2.67 parts of 97% silicon carbide micropowder with a particle size of 3 μm, and 2.67 parts of Si-NO micropowder with a particle size of 0.5-20 μm. That is, the mass ratio of metallic silicon powder, silicon carbide micropowder, and Si-NO micropowder is 1:1:1.

[0142] The preparation method of the refractory castable for the low nickel matte chute described in this embodiment is the same as that in Example 2.

[0143] Example 16

[0144] The low-grade nickel matte chute refractory castable of this embodiment is prepared using the same raw materials and the same proportions as in Example 2, with the following differences: the antioxidant contains 1.6 parts of metallic silicon powder, 3.2 parts of 97% silicon carbide micropowder with a particle size of 3 μm, and 3.2 parts of Si-NO micropowder with a particle size of 0.5-20 μm. That is, the mass ratio of metallic silicon powder, silicon carbide micropowder, and Si-NO micropowder is 1:2:2.

[0145] The preparation method of the refractory castable for the low nickel matte chute described in this embodiment is the same as that in Example 2.

[0146] Example 17

[0147] The low-grade nickel matte chute refractory castable of this embodiment is prepared using the same raw materials and the same proportions as in Example 2, with the following differences: the antioxidant comprises 3 parts of metallic silicon powder, 2.5 parts of 97% silicon carbide micropowder with a particle size of 3 μm, and 2.5 parts of Si-NO micropowder with a particle size of 0.5-20 μm. In other words, the mass ratio of metallic silicon powder, silicon carbide micropowder, and Si-NO micropowder is 1:0.83:0.83.

[0148] The preparation method of the refractory castable for the low nickel matte chute described in this embodiment is the same as that in Example 2.

[0149] Example 18

[0150] The remaining components and proportions of the raw materials used in the preparation of the low-grade nickel matte chute of this embodiment are the same as those of Example 2, with the difference that the antioxidant contains 1 part of metallic silicon powder, 3.5 parts of 97% silicon carbide micropowder with a particle size of 3 μm, and 3.5 parts of Si-NO micropowder with a particle size of 0.5-20 μm. That is, the mass ratio of metallic silicon powder, silicon carbide micropowder, and Si-NO micropowder is 1:3.5:3.5.

[0151] The preparation method of the refractory castable for the low nickel matte chute described in this embodiment is the same as that in Example 2.

[0152] Example 19

[0153] The remaining raw material components and proportions of the low-grade nickel matte chute refractory castable in this embodiment are the same as those in Example 2, with the following differences: 9.6 parts of alumina powder; 1.5 parts of metallic silicon powder, 2.25 parts of 97% silicon carbide powder with a particle size of 3 μm, and 2.25 parts of Si-NO3 powder with a particle size of 0.5-20 μm. That is, the mass ratio of metallic silicon powder, silicon carbide powder, and Si-NO3 powder remains unchanged, while the mass ratio of alumina powder to antioxidant is 1:0.625.

[0154] The preparation method of the refractory castable for the low nickel matte chute described in this embodiment is the same as that in Example 2.

[0155] Example 20

[0156] The remaining raw material components and proportions of the low-grade nickel matte chute refractory castable in this embodiment are the same as those in Example 2, with the following differences: 7.1 parts of alumina powder; 2.2 parts of metallic silicon powder, 3.3 parts of 97% silicon carbide powder with a particle size of 3 μm, and 3.3 parts of Si-NO3 powder with a particle size of 0.5-20 μm, respectively. The mass ratio of metallic silicon powder, silicon carbide powder, and Si-NO3 powder remains unchanged, while the mass ratio of alumina powder to antioxidant is 1:1.24.

[0157] The preparation method of the refractory castable for the low nickel matte chute described in this embodiment is the same as that in Example 2.

[0158] Example 21

[0159] The remaining raw material components and proportions of the low-grade nickel matte chute refractory castable in this embodiment are the same as those in Example 2, with the following differences: 10 parts alumina powder; 1.4 parts metallic silicon powder, 2.1 parts 97% silicon carbide powder with a particle size of 3 μm, and 2.1 parts Si-NO3 powder with a particle size of 0.5-20 μm. The mass ratio of metallic silicon powder, silicon carbide powder, and Si-NO3 powder remains unchanged, while the mass ratio of alumina powder to antioxidant is 1:0.56.

[0160] The preparation method of the refractory castable for the low nickel matte chute described in this embodiment is the same as that in Example 2.

[0161] Example 22

[0162] The remaining raw material components and proportions of the low-grade nickel matte chute refractory castable in this embodiment are the same as those in Example 2, with the following differences: 6 parts of alumina powder; 2.5 parts of metallic silicon powder, 3.75 parts of 97% silicon carbide powder with a particle size of 3 μm, and 3.75 parts of Si-NO3 powder with a particle size of 0.5-20 μm. That is, the mass ratio of metallic silicon powder, silicon carbide powder, and Si-NO3 powder remains unchanged, while the mass ratio of alumina powder to antioxidant is 1:1.67.

[0163] Comparative Example 1

[0164] The refractory castable for the low nickel matte chute in this comparative example has the same raw material components and mass fractions as those in Example 2, except that the 88 homogenized alumina particles with a particle size of 8 to 15 mm are replaced by brown corundum with a particle size of 8 to 15 mm.

[0165] The preparation method of the refractory castable for the low nickel matte chute in this comparative example is the same as that in Example 2.

[0166] Comparative Example 2

[0167] The refractory castable for low nickel matte chute in this comparative example has the same other components and mass fractions of raw materials as those in Example 2, except that the brown corundum and dense corundum particles are replaced by homogenized alumina particles, that is, 14 parts of brown corundum particles with a particle size of 5-8 mm, 15 parts of brown corundum particles with a particle size of 3-5 mm, and 3 parts of dense corundum particles with a particle size of 1-3 mm are replaced by 14 parts of homogenized alumina particles with a particle size of 5-8 mm, 15 parts of homogenized alumina particles with a particle size of 3-5 mm, and 3 parts of homogenized alumina particles with a particle size of 1-3 mm.

[0168] Comparative Example 3

[0169] In the preparation of the refractory castable for the low nickel matte chute in this comparative example, the addition amounts of alumina powder, binder, antioxidant, carbon material, metallic aluminum, explosion-proof fiber, water reducer and boron carbide are the same as those in Example 2, except that the proportions of alumina, corundum and silicon carbide are adjusted so that the total amount of silicon carbide particles and fine powder is 22 parts.

[0170] In this embodiment, the raw materials are prepared as follows: 6 parts of 88 homogenized alumina particles with a particle size of 8-15 mm, 14 parts of brown corundum particles with a particle size of 5-8 mm, 15 parts of brown corundum particles with a particle size of 3-5 mm, 15 parts of dense corundum particles with a particle size of 1-3 mm, 4 parts of dense corundum particles with a particle size of 0.1-1 mm, 2 parts of dense corundum fine powder with a particle size of 200 mesh, 0 parts of 97 silicon carbide particles with a particle size of 1-3 mm, 13 parts of silicon carbide particles with a particle size of 0.1-1 mm, 7 parts of silicon carbide fine powder with a particle size of 200 mesh, and 2 parts of silicon carbide fine powder with a particle size of 325 mesh.

[0171] Comparative Example 4

[0172] In the preparation of the refractory castable for the low nickel matte chute in this comparative example, the addition amounts of alumina powder, binder, antioxidant, carbon material, metallic aluminum, explosion-proof fiber, water reducer and boron carbide are the same as those in Example 2, except that the proportions of alumina, corundum and silicon carbide are adjusted so that the total amount of silicon carbide particles and fine powder is 43 parts.

[0173] In this embodiment, the raw materials are prepared as follows: 6 parts of 88 homogenized alumina particles with a particle size of 8-15 mm, 14 parts of brown corundum particles with a particle size of 5-8 mm, 15 parts of brown corundum particles with a particle size of 3-5 mm, 0 parts of dense corundum particles with a particle size of 1-3 mm, 0 parts of dense corundum particles with a particle size of 0.1-1 mm, 0 parts of dense corundum fine powder with a particle size of 200 mesh, 15 parts of 97 silicon carbide particles with a particle size of 1-3 mm, 17 parts of silicon carbide particles with a particle size of 0.1-1 mm, 9 parts of silicon carbide fine powder with a particle size of 200 mesh, and 2 parts of silicon carbide fine powder with a particle size of 325 mesh.

[0174] Comparative Example 5

[0175] The low-matte nickel chute refractory castable in this comparative example is prepared with raw materials, and the remaining components and proportions are the same as those in Example 2, except that the alumina powder is adjusted to 8.75 parts and the aluminate cement is 0 parts.

[0176] Comparative Example 6

[0177] The low-matte nickel chute refractory castable in this comparative example is prepared with raw materials, and the remaining components and proportions are the same as those in Example 3, except that the alumina powder is adjusted to 6.5 parts and the silicon powder in the binder is adjusted to 3 parts.

[0178] Comparative Example 7

[0179] The refractory castable for the low nickel matte chute in this comparative example is prepared by using raw materials, and the remaining components and proportions are the same as those in Example 3, except that the alumina powder is adjusted to 7.7 parts and the aluminate cement in the binder is adjusted to 1 part.

[0180] The hardening time, strength, oxidation performance, and corrosion resistance of the refractory castables for low-matte nickel chutes in the above-mentioned embodiments and comparative examples were tested. The oxidation performance test used the area ratio of the oxidized area on the cross section, and the corrosion resistance was tested using the static crucible method. The test results are shown in Table 1 below.

[0181] Table 1

[0182]

[0183] It can be seen from the data in Table 1 that compared with Examples 1, 2, and 3, the refractory castables for low-matte nickel chutes using different binders show different characteristics. Example 1 uses conventional cement and silica differential bonding, and has better room temperature strength than Examples 2 and 3, but lower high temperature strength, oxidation rate, and erosion rate. Under cold construction conditions, Example 1 can meet the use conditions of low-matte nickel chutes after oxidation and baking processes. Example 2 has a longer hardening time, but its high temperature strength, oxidation rate, and erosion rate are higher than those of Example 1. After the construction is completed, it can be quickly baked to increase the strength. It is more suitable for construction conditions with a certain temperature and has better use effect. Compared with Examples 1 and 2, Example 3 has lower room temperature strength and shorter construction time, but has the best high temperature strength, anti-oxidation and anti-erosion properties. It is more suitable for hot construction and is carried out by pouring or ramming. It generates strength quickly and can be put into use in a short time, significantly shortening the construction time and having a high service life.

[0184] In Comparative Example 1, the homogenized alumina in the aggregate is replaced with brown corundum, and in Example 4, the granular material is replaced with iron ditch recycled material. Compared with the use of part of the alumina in the aggregate in Example 2, the various performances of Comparative Example 1 and Example 4 are slightly lower than those of Example 2, and can meet the use requirements. However, in Comparative Example 1, brown corundum is usually more expensive than homogenized alumina, so the cost is higher, but the performance is slightly worse. Although the performance indicators of Example 4 are slightly worse, the average price of brown corundum in the same period is 5250 yuan / ton, and the price of recycled material is 3850 yuan / ton. It can be seen that the use of iron ditch recycled material slightly reduces the performance, but on the basis of ensuring the performance of the castable, the material cost of the castable is significantly reduced, and the recycling of resources is promoted, reducing waste emissions.

[0185] Compared with Example 2, Examples 5, 6, and 7 differ in the number of parts of silicon carbide micropowder added. 3 parts of 97 silicon carbide micropowder added in Example 2 have the best strength, antioxidant and erosion resistance. When the addition amount is reduced, the micropowder is insufficient in filling the castable matrix, the castable porosity is high, and the antioxidant and erosion resistance are slightly poor. When the addition amount is increased, the castable viscosity increases and the fluidity deteriorates, resulting in a significant increase in the pores in the castable matrix and a serious deterioration in the antioxidant and erosion resistance. This shows that when the mass parts of other components are the same, the addition amount of 97 silicon carbide micropowder in Example 2 is preferred, which plays a role in improving the performance indicators of the castable.

[0186] Compared with Example 2, Examples 8, 9, and 10 have different amounts of Si-NO powder added. As the mass fraction of Si-NO powder added in the antioxidant increases, the oxidation rate of the castable gradually decreases, and the erosion first decreases and then increases. When the amount of Si-NO powder added reaches 3 parts, the erosion rate of the castable reaches the lowest and the mechanical properties reach the optimal value. Excessive Si-NO powder will affect the fluidity of the castable, increase the liquid phase ratio in the matrix, and lead to a decrease in mechanical properties and erosion resistance. Therefore, when the mass fractions of other components in the raw materials remain unchanged, the appropriate addition of Si-NO powder can improve the overall performance of the castable.

[0187] The difference between Examples 2, 11, 12, 13, and 14 is the mass fraction of each component. Among them, the mass fraction of each component of the raw materials of Examples 2, 11, and 12 is within the preferred range, and their comprehensive performance such as mechanical properties, corrosion resistance, and antioxidant properties are better than those of Examples 13 and 14.

[0188] Compared with Examples 2, 15, 16, 17, and 18, the difference is that the proportions of metallic silicon powder, silicon carbide micropowder, and Si-NO micropowder in the antioxidant are different. Among them, the proportions of metallic silicon powder, silicon carbide micropowder, and Si-NO micropowder in Examples 2, 15, and 16 are within the preferred range, and their comprehensive performance such as mechanical properties, corrosion resistance, and antioxidant properties are better than those of Examples 17 and 18.

[0189] The difference between Examples 2, 19, 20, 21, and 22 lies in the different mass ratios of alumina powder to antioxidant. Among them, the mass ratios of alumina powder to antioxidant in Examples 2, 19, and 20 are within the preferred range, and their comprehensive performance, including mechanical properties, corrosion resistance, and antioxidant properties, is superior to that of Examples 21 and 22.

[0190] Comparative Example 2, in which all the brown corundum and dense corundum in the particles were replaced with 88 homogenized alumina, exhibited a shortened hardening time, improved strength, and increased strengthening and erosion rates. This is because 88 homogenized alumina has high water absorption, is easily sintered, and has high porosity, resulting in a shorter hardening time. 88 homogenized alumina also has a high impurity content, and the low calcination temperature during the alumina raw material production process makes it easier to sinter at high temperatures, resulting in improved strength at high temperatures. However, the high porosity of 88 homogenized alumina makes the sample more susceptible to oxidation and slag penetration and erosion, leading to increased oxidation and erosion rates.

[0191] Comparative Example 3, Example 2, and Comparative Example 4, respectively, contain 22, 38, and 43 parts of silicon carbide granules and fine powder. The experimental results show that increasing the silicon carbide addition ratio increases the hardening time, decreases the strength, and increases the oxidation and erosion rates. Appropriate silicon carbide addition can improve the overall performance of the castable.

[0192] Compared to Example 2, in Comparative Example 5, the omission of cement significantly increased the sample's hardening time and significantly decreased its strength. Demolding was impossible for extended periods, and after demolding, due to low strength, microcracks developed during baking, leading to an increased erosion rate. Therefore, the addition of a small amount of cement in Example 2 is necessary to ensure the castable's workability, ensuring an appropriate hardening time and demolding strength, while also preventing cracking and bulging of the cast during high-temperature baking.

[0193] Comparative Example 6, compared to Example 3, increases the amount of silica powder added. The test results show that the addition of silica powder disrupts the equilibrium system of the silica sol, causing the sample to react rapidly and lose fluidity, resulting in low strength, high porosity, and significantly increased oxidation and erosion rates. Therefore, an appropriate ratio of silica powder, silica sol, and cement in a silica sol system can improve the castable's workability while also filling pores and improving strength and erosion resistance.

[0194] Comparative Example 7 differs from Example 3 in the amount of aluminate cement added. Adding an appropriate amount of aluminate cement can promote the curing reaction of the silica sol. If the amount is too small, the castable will not harden for a long time, resulting in low strength and impractical demolding. However, if too much cement is added, the castable will quickly lose fluidity, failing to meet construction requirements, making sample preparation impossible and poor workability.

[0195] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A refractory castable for a low nickel matte chute, characterized in that: The raw materials for its preparation include the following components in parts by mass: 6-15 parts of alumina particles or recycled particles thereof, 25-40 parts of corundum particles or recycled particles thereof, 20-30 parts of silicon carbide particles or recycled particles thereof, 1-10 parts of corundum fine powder, 5-15 parts of silicon carbide fine powder, 4-10 parts of alumina micropowder, 3.4-10 parts of binder, 3-10 parts of antioxidant, and 2-4 parts of carbon material; wherein the antioxidant is a combination of metallic silicon powder, silicon carbide micropowder, and Si-NO micropowder in a mass ratio of 2:2-4:2-4.

2. The refractory castable for low nickel matte chute according to claim 1, characterized in that: The raw materials for its preparation include the following components in parts by mass: 6-10 parts of alumina particles or their recycled particles, 28-35 parts of corundum particles or their recycled particles, 25-30 parts of silicon carbide particles or their recycled particles, 1-5 parts of corundum fine powder, 6-10 parts of silicon carbide fine powder, 6-10 parts of alumina micropowder, 3.4-7 parts of binder, 5-9 parts of antioxidant, and 2-3 parts of carbon material.

3. The refractory castable for low nickel matte chute according to claim 1, characterized in that: The mass ratio of alumina powder to antioxidant is 1:0.625~1.

25.

4. The refractory castable for low nickel matte chute according to claim 1, characterized in that: The binder is a mixture of silica fine powder and aluminate cement in a mass ratio of 1:0.5~1.5, or a mixture of silica fine powder, Cyc-Z, and aluminate cement in a mass ratio of 0.7:2~3:0.5~1.5, or a mixture of silica fine powder, silica sol, and aluminate cement in a mass ratio of 1.5:4~6:0.6~0.

8.

5. The refractory castable for low nickel matte chute according to claim 1, characterized in that: The following components are also included in parts by weight: 0.1~0.3 parts of water reducing agent, 0.2~0.8 parts of boron carbide, and 0.07~0.25 parts of explosion-proof agent.

6. The refractory castable for low nickel matte chute according to claim 5, characterized in that: The silicon carbide particles or the recycled particles thereof are composed of silicon carbide particles or the recycled particles thereof with a particle size of 1 to 3 mm and silicon carbide particles or the recycled particles thereof with a particle size of 0.1 to 1 mm, mixed in a mass ratio of 10 to 13:14 to 17; The silicon carbide fine powder is composed of 200-mesh silicon carbide fine powder and 325-mesh silicon carbide fine powder mixed in a mass ratio of 5-10:1-4; The particle size of silicon carbide powder is 1~5μm; The corundum particles or the recovered particles thereof include brown corundum particles or the recovered particles thereof with a particle size of 5-8 mm, brown corundum particles or the recovered particles thereof with a particle size of 3-5 mm, and dense corundum particles or the recovered particles thereof with a particle size of 1-3 mm; the mass ratio of alumina particles or the recovered particles thereof with a particle size of 8-15 mm, brown corundum particles or the recovered particles thereof with a particle size of 5-8 mm, brown corundum particles or the recovered particles thereof with a particle size of 3-5 mm, and dense corundum particles or the recovered particles thereof with a particle size of 1-3 mm is 6-10:12-17:14-17:2-5; The particle size of the corundum fine powder is 200 mesh; The particle size of the alumina particles or the recovered particles is 8 to 15 mm; The particle size of metallic silicon powder is 3~40μm; The particle size of Si-NO powder is 0.5~20μm; The particle size of alumina powder is 2~5μm; The particle size of carbon material is 0.001~2mm; The particle size of boron carbide is 325 mesh.

7. The refractory castable for low nickel matte chute according to claim 5, characterized in that: The content of Al2O3 in alumina particles is not less than 87wt%, the content of Fe2O3 is not higher than 1.55%, the porosity is less than 5.5%, and the bulk density is greater than 3.3g / cm 3 ; The Al2O3 content in the recovered alumina pellets and corundum pellets is not less than 90wt%, and the bulk density is ≥3.7g / cm 3 ; The SiC content in the silicon carbide particles is not less than 92wt%; The SiC content in the silicon carbide fine powder is not less than 97wt%; The SiO2 content in the silica powder is not less than 92wt%; The SiO2 content in the silica sol is 39wt%~41wt%, the pH is 9~10.5 at 25℃, and the viscosity is 10~20mPa·s; The Al2O3 content in aluminate cement is not less than 70wt%.

8. The refractory castable for low nickel matte chute according to claim 5, characterized in that: The carbon material is one or a combination of spherical pitch, graphite, and carbon black; The water reducer is one or a combination of SP610, FS20, FDN, DF401, PC8159, and BC-2; The explosion-proof agent is one or a combination of metal aluminum powder and explosion-proof fiber.

9. A method for preparing a refractory castable for a low-matte nickel chute according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. The raw materials of the antioxidant are mixed to obtain an antioxidant mixture; S2. The antioxidant mixture and the binder are mixed to obtain a premix; S3. Mix alumina particles or their recycled particles, corundum particles or their recycled particles, silicon carbide particles or their recycled particles, corundum fine powder, silicon carbide fine powder, alumina micropowder, carbon material, and premix to obtain the refractory castable for the low nickel matte chute, wherein silica sol is added to the binder when in use.

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